Suckermouth catfish have overrun our rivers. Who’s fighting back?
The battle against invasive species is a long and grueling one, but it is winnable. The first step is recognising that the locals on the frontlines are not just individuals fighting a losing battle
Last week, BBC News featured an inspiring story of local women in the Caribbean fighting back against an ecological menace.
Armed with fishing spears, chef Helmi Smeulders and dive instructor Lisette Keus are diving deep into the Caribbean waters to hunt down the invasive, ravenous and predatory lionfish and save small and fragile reef-dwelling fish. Their efforts have garnered global attention, illustrating how local action can drive impactful conservation solutions.
Thousands of miles away, on the murky banks of the Buriganga River in Bangladesh, another strikingly similar battle is underway.
Fazlu Miah, an artisanal fisherman, has been pulling thousands of suckermouth catfish from the river. Without scientific training, he still inspired a whole community for the job and showed that controlling harmful alien species goes beyond merely banning them on paper.
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Both fish are of global conservation concern. Introduced through the aquarium trade, these species have spread beyond their range and overrun native fisheries, disrupting livelihoods and threatening biodiversity.
Unlike the Caribbean huntresses, Fazlu and many other affected artisanal fishers work alone, without institutional support, media recognition or financial incentives. Yet, their efforts are just as crucial in mitigating ecological damage.
The devastation wrought by invasive species
Lionfish and suckermouth catfish may seem worlds apart, but both species are wreaking havoc in ecosystems where they do not belong.
Lionfish, native to the Indo-Pacific, were introduced to the Atlantic waters. These expert stalkers simply hover in the water column, ambushing unsuspecting prey. Their venomous spines deter almost all natural predators, allowing them to reproduce unchecked. Lionfish have decimated many native reef fish populations, disrupting food webs and endangering commercial fisheries.
It was not until the reef fish diversity collapse became evident that the world took action. But by then, it was already too late for many marine ecosystems.
Suckermouth catfish, similarly, have spread far beyond their native South American habitats. In Bangladesh, these armored fish are grazers and have a remarkable ability to thrive in almost all conditions.
Thus, they have outcompeted native species, eroded river banks with their burrowing behaviour, and rendered traditional fishing methods ineffective.
Initially popular in aquariums due to their algae-eating habits, they are usually released into the wild once they overgrow the tank. Unlike lionfish, which have become the subject of coordinated removal efforts, suckermouth catfish remains an unresolved issue.
Sadly, the discussions are mostly confined to academic seminars, banning the fish on paper and social media outrage rather than concrete action. But the Fazlu Miahs are our Nick Furys, showing the way to stop the secret invasions.
Global problem, local solutions
The spread of invasive species is not a new phenomenon, but it continues to be underestimated.
Whether it is the Burmese python in the Florida Everglades, the Asian carp in North American rivers, or the cane toad in Australia, history repeatedly shows that invasive species flourish when introduced to environments with no natural predators.
Yet, the response to these crises is often slow and disjointed, and by the time action is taken, the ecological damage is already extensive.
What the Caribbean lionfish huntresses and the Bangladeshi artisanal fishers demonstrate is that local communities are often the first to respond, long before conservation organisations and policymakers get involved.
Their efforts, however, are rarely recognised or supported. The success of lionfish removal in the Caribbean came not just from grassroots action, but from a coordinated effort involving conservationists, tourism industries and government policies.
Could similar systemic solutions be applied in Bangladesh and other affected areas?
The need for systemic solutions
Rather than addressing invasive species removal as isolated incidents, we need to understand the interconnected factors that determine success.
In the Caribbean, multiple sectors — tourism, fisheries and conservation — work together to tackle the lionfish problem. In Bangladesh, a similar integrated approach could help turn suckerfish removal into an opportunity.
One of the biggest drivers behind successful lionfish removal has been the creation of a market for their consumption. Could something similar be done with suckermouth catfish?
Suckermouth catfish have spread far beyond their native South American habitats. In Bangladesh, these armored fish are grazers and have a remarkable ability to thrive in almost all conditions. Thus, they have outcompeted native species, eroded river banks with their burrowing behaviour, and rendered traditional fishing methods ineffective.
While their tough, bony structure makes them difficult to eat, alternative uses such as fishmeal, animal feed, or even fertiliser could be explored. By creating an economic incentive, more people would be encouraged to remove them from the water. To stop alien species that are prolific breeders and more adaptable than native fauna, there is no substitute for regular removal sessions.
Furthermore, the involvement of local fishermen and communities is crucial. Like the Buriganga fishers' community that stepped up, there are likely many others who would be willing to participate in suckerfish removal efforts if provided with the right incentives and resources. Community-driven fishing programmes could be established, much like in the Caribbean, where organised lionfish culling events are held.
The government must also step in with clear policies. One of the biggest reasons why suckerfish remain a problem in Bangladesh is the lack of timely enforcement regarding the release of non-native species. Suckermouth catfish has become a concern only when it is evident that local fish are disappearing.
Moreover, many people do not realise the damage caused by releasing exotic species into the wild. Awareness campaigns, particularly targeted at aquarium owners, could help prevent further introductions of invasive species. Additionally, promoting the stories of people like Fazlu Miah could inspire greater public engagement in tackling the issue.
Connecting science, policy and local measures
What is now happening in the Buriganga underscores the importance of community-driven conservation, yet it also reveals the need for structural support.
Recognition alone is not enough — effective solutions require linking grassroots efforts with economic and policy frameworks.
Bangladesh's problem with suckermouth catfish is not going to be solved by social media discussions or seminar presentations alone.
Importing, breeding and trading in this species is already banned. But who will remove the fish that have already spread? And, how to achieve this? There is absolutely no direction from the authorities whatsoever.
Systems thinking in conservation
The challenge of managing invasive species is a classic example of why systems thinking is crucial in conservation.
In isolation, removing lionfish or suckerfish may seem like a simple ecological intervention, but the reality is far more complex. Ecosystems operate as intricate networks of interactions, where changes in one component can have cascading effects across the entire system.
For instance, while the removal of lionfish in the Caribbean has been successful at a local level, it requires an understanding of how human behavior, market forces and ecological dynamics intersect. The biology and ecology of lionfish have also been studied with a vested interest in deciding on culling intensity and identifying worst-hit areas.
The same principle applies to the suckerfish problem in Bangladesh. Without addressing the economic, regulatory and community-based factors that contribute to their spread, any removal effort will be short-lived.
Unfortunately, the problem of suckermouth catfish has been brought to the spotlight in recent years. Its identity was fixed only in 2008 and, other than some maps drawn based on media reports, we do not have any information on how to stop this rapidly spreading resilient species of fish.
Thus, a true solution requires long-term planning, interdisciplinary collaboration and the integration of traditional ecological knowledge with socio-economic considerations.
By applying systems thinking, we can move beyond short-term fixes and develop sustainable approaches that not only remove invasive species but also prevent future invasions.
The battle against invasive species is a long and grueling one, but it is winnable. The first step is recognising that the people on the frontlines — whether they are divers in the Caribbean or fishers of the Buriganga — are not just individuals fighting a losing battle.
The Caribbean has shown that coordinated efforts can turn an invasive species problem into an opportunity. The question is: Will Bangladesh follow suit, or shall we continue to howl on paper and watch as our waterways are overrun?
